The Coming Great Quakes in India and Bangladesh?

October 19, 2016

A new film takes viewers from the eastern highlands of India to the booming lowland metropolis of Dhaka, the capital of Bangladesh—and explores an ever-more detailed picture of catastrophic earthquake threat that scientists are discovering under the region.

Scientists from Columbia University’s Lamont-Doherty Earth Observatory, the University of Dhaka and other institutions have been working for more than a decade to understand deeply buried geologic structures that could produce earthquakes here, one of the most densely populated places on earth. No one can predict when the next quake will strike, or how big it will be—but clearly there is potential for a very large one. “Some of this have long suspected this hazard, but we didn’t have the data and a model,” says Lamont-Doherty geophysicist Michael Steckler, leader of a recently published study outlining the threat.

Under Bangladesh, India and neighboring Myanmar, the scientists have found signs of a megathrust—the meeting of two gigantic moving tectonic plates, with one diving under the other. But the plates don’t seem to be moving right now; they are locked, and strain is building. The researchers say that when—not if—the plates do slip, destruction and casualties could be massive. Some 140 million people might be affected.

The hazard has been hard to assess up to now, because most of the region’s underlying geology is covered by the world’s largest river delta—miles-deep layers of sediment carried down from the Himalayas and built up over millennia. The team has deployed seismometers, GPS instruments, satellite imagery and other technology to draw up a picture of what is going on down below.

The region is unprepared. Not only are many people too poor to build earthquake-resistant structures. “From history, there’s been a lot of destructive earthquakes in this area, but there hasn’t been one in recent years, so people tend to forget,” said Lamont-Doherty geologist Leonardo Seeber. Geologist Humayun Akhter of the University of Dhaka, said, “Our cities are not built in a planned way, and this cannot be changed in a few years. So we have to work within this system, and teach our people how to cope.”

The movie was made by filmmakers Douglas Prose and Diane LaMacchia with support from the U.S. National Science Foundation. The NSF also funded the research.